Pressure sensitive decalcomania and method of making the same



Sept. 4, 1951 A. F. GRUPP EIAL 2,567,067

PRESSURE SENSITIVE DECALCOMANIA AND METHOD OF MAKING THE SAME Filed Nov.29, 1947 C-CLEAF' LA CQUEI? PRO 750 H vs com P-COL 0/? PRINT/N6f/IIIII/IIII/III/IIlIIIIII/IIIIIIlI/(IlIl/IIII/IllldlIII/IIIIl/A AC TlVA TIN G COAT W" 7 m N X CARRIER 51/551 R- RES/NOUS ADHESIVE, D- WATERSOLUBLE NORMALLY NON-TACKY AND cum (05x TRINE) NON-PRESSURE SENSITIVEomnh S-SEALER COAT @ZfreaZFGr Harry 6.150%

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Patented Sept. 4, 1951 PRESSURE SENSITIVE DECALCOMANIA AND METHOD OFMAKING THE SAME Alfred F. Grupp, Glen Ellyn, Harry G. Rathkeand ElwoodS. Talan, Chicago, Ill., and Elmore Watts, Mission, Kans., assignors toThe Meyer- ,cord 0.0., Chicago, 111., a corporation of IllinoisApplication November 29, 1947, SerialNo. 788,816

.16 .Claims. 1

This invention relates to a novel transfer of the decalcomania type andto amethod of manufacturing the same.

*Heretofore, pressure sensitive decalcomanias have been produced andused with varying degrees ,of success. Generally, in the use of suchdecal'comanias, a paper backing is removed from the 'decalcoma-nia inthe usualmarmer by soaking in water thereby exposing a tacky, pressuresensitive, adhesive layer which may be applied directly to the surfaceto "be decorated. Upon'the application of pressure, the'transfer iscaused to adhere to the surface.

Pressure sensitivity has long been recognized as a desirable property ina decalcomania since it-provides a quick, effective-and simple means forapplying the transfer without the necessity of using solvents andspecialadhesives. :However, numerous difilculties and disadvantages havebeen encountered and they "have made it impossible heretofore "toproducea satisfactoryipressure sensitive decalcomania in :a quick,inexpensive, and simple manner. For example-the pressure sensitiveadhesives, which :remain tacky during production and over an extendedportion of the life of the :decalcomania, are not directly printable andnormally require-the application of a sealer coating over the adhesivelayer in order to *overcome the tackiness and to provide aiirm, nontackysurface capable of receiving an imprint without running and withoutadhering to the printing :rolls or screens. Moreover, :during themanufacturing process, the'resul-tant wet transfer .sheets possess ahigh degree of tack and consequently are notstackable necessitating the.pro-

vision of elaborate and bulky drying .racks .to permit the individualdecalcomania sheets to be .stored out ofcontact with .eachother until.ap

;.plication of the sealer coating. 1

Another disadvantage possessed by the known types of pressure sensitivedecalcomanias is that the adhesive tends to remain in a normally tackycondition for some-period of time after application to a suriace therebypermitting the decalcomanias to be removed without destruction thereof.Such ease of removal is highlyundesira- .ble particularly Where it isnecessary .to guard against theft and re-use. It has also been foundthat the pressure sensitivity and normal tackiness of such adhesivelayers finally disappear and the adhesive becomes dry and cracks after aconsiderable period .of time with the result that the -decalccmaniabecomes loosened and often falls from the surface to which it:hasbeenor-igzinal-ly applied. v

One object of the present invention is to pro-- vide a noveldecalcomania transfer which has pressure sensitive properties in theadhesive layer but which is not subject to the many disadvantages anddifficulties previouly associated with the production of a pressuresensitive type decalcomania.

Another objectof the invention is to provide a decalcomania which haspressure sensitive properties and yet is readily stackable during itsmanufacture, particularly after the application of the adhesive layer.

Another object of the invention is to provide a decalcomania havingpressure sensitive properties but which does not require the use of .asealer layer.

Still another objectis to'provide a decalcomania of the pressuresensitive type in which the adhesive layer, after being applied to thecarrier paper, quickly dries to a substantially dry, nontacky, andnon-pressure sensitive adhesive thereby permitting the sheets to bestacked during production without adhering to each other while awaitingapplication of the design prints, the adhesive layer, however, being ofsuch properties as to become pressuresensitive and tacky uponapplication of additional layers thereover.

A still further object of the invention is to provide a noveldecalcomania which possesses pressure sensitive properties serving toprovide a preliminary adhesive "bond for holding the decalcomania inplace when first applied to a surface and which, with the passage oftime, develops a permanent, tough, strong, scratch resistant, adhesive.bond with said surface.

An additional object of the invention is to provide a novel decalcomaniaof the pressure sensitive type in which the degree of tack or pressuresensitivity of the adhesive may be controlled or varied in accordancewith the uses to which the decalcomania is to be putand thereby adaptingit forapplication to awide variety of rough, porous, plastic, ormetallic surfaces.

Another object of the invention is to provide a novel decalcomania inwhich the adhesive stratum as initially applied is normally non-tackyand non-pressure sensitive but which, after the application ofsubsequent layers, is converted by the action of plasticizing oils "insaid subsequent layers to a tacky, pressure sensitive stratum.

A decalcomania transfer consists ordinarily of a relatively heavyabsorbent type paper backing coated with a water soluble adhesive or gumto which are applied a plurality of additional strata or films such as awater insoluble adhesive layer,

a transfer design in color, and a protective coating. The decalcomaniaof the present invention difiers from the decalcomanias previously knownby the provision of a plurality of independent but interacting layers ofwhich one layer comprises a resinous, normally non-pressure sensitivematerial and of which at least one other layer contains one or moreplasticizers capable of migrating or diffusing into the resinous layerto convert the latter into a tacky, pressure sensitive adhesive.Inasmuch as the potential pressure sensitivity of the adhesive layerdoes not develop until after migration of the plasticizing oils hasoccurred, it will be apparent that our decalcomania is based upon whatmay be characterized as a delayed action principle, and as a result weare able to avoid the printing and stacking difilculties previouslyencountered in the production of a pressure sensitive decalcomania.

The major component of the adhesive layer of our decalcomania is athermoplastic, water insoluble, non-oxidizing resin which is normallynontacky and non-pressure sensitive but which is capable of beingconverted by the action of a suitableplasticizer to a tacky, pressuresensitive condition. The adhesive stratum is applied in the form of asolution of the resin in a suitable quick-drying solvent or vehicle.After evaporation of the solvent which occurs after the lapse of a veryshort time, the dry adhesive layer is non-tacky and non-pressuresensitive and may be stacked or printed upon in the customary mannerwithout difliculty; In one embodiment of the invention an activatinglac'quer or coating containing an appropriate and predetermined amountof plasticizer for the resin may be applied preferably directly over theadhesive layer, although the juxtaposition of the adhesive andactivating strata is not essential, and after a suitable period of timehas elapsed, the plasticizing oils will have migrated or diffused intothe adhesive layer converting the resinous constituent thereof to atacky, pressure sensitive material. In other embodiments of theinvention no special activating layer is employed, but the normalplasticizer content of the various layers of printing lacquers formingthe transfer design is sufilcient to migrate into the resinous adhesivelayer and render it tacky. The plasticizing oils thus serve to createtackiness in the adhesive layer as well as to maintain the lacquers in aflexible state but the tackiness of the adhesive layer does not in anyway prevent the activating lacquer or the printing lacquers from dryingto a non-tacky state. By varying the resin content of the adhesivelayer, the thickness of the layer, and the amount and character of theplasticizer in the activating and later printed layers, the degree oftackiness or pressure sensitivity may be controlled within definitelimits.

The mechanism and structure of the decalcomanias of the presentinvention will become more apparent by reference to the drawing whereinseveral alternative arrangements embodying the migration principle areillustrated in cross-section with the various strata or films shown inexaggerated thickness for the sake of clarity.

Similar reference characters are employed to designate correspondingstrata throughout the several views, the letter B referring generally toa paper backing, D to a water soluble gum such as dextrine, R to a waterinsoluble, resinous adhesive layer which is originally non-pressuresensitive but later assumes pressure sensitive characteristics, A to anactivating coating containin which the activating coat is applied overthe color printing layer and the adhesive layer is superimposed directlyover the activating coat.

Fig. 4 is still another embodiment of the invention in which no specialactivating layer is employed and in which the migratory plasticizingoils are supplied in the layers of printing lacquer applied over theresinous adhesive layer.

Fig. 5 shows a "reserve type decalcomania in which the resinous adhesivelayer is applied directly over the printing layer and no specialactivating layer is employed.

Referring to the form of decalcomania shown in Fig. 1, the layer B is apaper backing or carrier of the absorbent type well known to thedecalcomania art. This paper is surfaced with a layer D of a watersoluble adhesive or gum such as dextrine, gelatine, gum tragacanth, etc.which, upon wetting with water, will permit the paper base or backing tobe removed from the transfer.

Over the layer D is applied by printing or screening in the usual mannera film R of a thermoplastic, non-oxidizing, water insoluble, normallynon-tacky and non-pressure sensitive resin in solution in a suitablequick-drying solvent. The resins which may be employed in the adhesivelayer R may be of a, relatively wide variety. The synthetic resins whichmay be used are the phenolic base resin-s, the vinyl acetate or chlorideresins, the cellulose acetate or nitrate resins, and

the polyvinyl alcohol resins, to mention only a few. Likewise, thehydrocarbon resins such as terpene polymers, styrene polymers, etc., andthe coal tar distillate resins such as the coumaroneindene resins,including polycoumarone, polyindone and copolymers of coumarone withindene and their homologs, may also serve effectively. A typicalcomposition which may be employed for the adhesive coating is asfollows:

Per cent Paracoumarone-indene resin (in solution) 48.6 Inert,transparent pigment 1.6 Dibutyl phthalate 0.1 Butyl Cellosolve (Z-butoxyethanol) 1.2 Hydrocarbon solvent 48.5

Another adhesive composition which has been found to give excellentresults is as follows:

Per cent Paracoumarone-indene resin (in solution) Ethyl cellulose 20After the solution of the resin has been applied over the layer D, thesolvent evaporates leaving behind a residual dry layer R which isnon-tacky and non-pressure sensitive. It is an important feature of ourinvention that the solvent selected cacao-av stage of their production.We have'foun'd that'b'y selecting a solvent of appropriate volatility orby blending several solvents to obtain thedesired degree of volatility,we can achieve a workable dry condition of the layer R in a relatively:short time, e. g. 15 to '20 minutes or less. Thereafter, the sheets maybe stacked one on top of the other while awaiting application of thedesign layers,

thus eliminating the necessity of space-consum- 'ing drying andseparating racks.

Over the layer R is then printed orscreened an activating layer A Whoseactive constituent is a jplasticizer or a mixture of plasticizershavingan afiinity for and capable of acting uponor reacting with theresinous component or the adhe'sive'layer R to impart to the latter thedesired de'gree'of tack'and pressure sensitivity. The activatin layer ispreferably in the form o'f 'a solution, such as a nitro-celluloselacquer, comprising a suitable solvent and a sufficient amount o'f-anappropriate plasticizer to migrate or diffuse from the activating'layerA to the adhesive layer R. Many types 'of plasticizers may be employedincluding the phthalate esters, such as dibutyl phth'alateand 'diphenylphthalate; the car-boxylic acid esters such as triacetin, butyl oleate,butyl acetyl ricinoleate, dibutyl sebacate, glyceryl sebacate, methylabietate, and triethyl-ene glycol hexoate; the phosphate esters such astributyl phosphate, tri- -cresyl phosphate, and diphenyl mono-(o-xenyl)phosphate, etc. In general, however, the selection and the formulationof the plasticizing components of the activating layer A are correlatedwith the type of resin in the adhesive layer R to obtain the desireddegree of pressure sensitivity.

We have obtained excellent results by employing for the activating layerA a normal outdoor lacquer containing glyceryl 'sebacate as aplasticizer. Another and more specific formula which we have found to besuitable for use in the layer A, particularly when the first adhesivecomposition specifically disclosed above is employed in the layer R, isas follows:

Per cent Nitro-cellulose 1550 D'ibutyl phthalate 1.4 Castor oil 21.0Butyl Cellosolve (2-butoxy ethanol) 46.7 Talc 1519 The foregoingcomposition is particularly useful where a clear activating coat isdesired. In in.- stances Where it may be desirable to employ an opaqueactivating layer to provide, for example, a white background for thesubsequent color print layers, the following activating layercompositionmay be used:

As soon as the activating layer A, containing the plasticizer for theresin 'in'the layer R, is

resin in the adhesive layer and that migration occursregardless of therelative positions of the two layers in the decalcomania provided, ofcourse, that there .is no sealing or isolating'stratum interposedbetween the activating and ad'- hesive layers which would prohibit thepassage of the plasticizer. The plasticizer, reaching the adhesive layerin'a relatively short time, imparts tacky and pressure sensitiveproperties to the resinous ingredient. The migration henomenon of theplasticizer continues over a relatively long period of time, e. g.'from2 to 30 days, and the degree of pressure sensitivity in the adhesivelayer .R increases with the extent of migration. The solvent contained'in the activating layer assists and initiates the migration of theplasticizer by preconditioning or penetrating the'dry adhesive filmahead of the plasticizer and by providing, in effect, a softer and morereceptive stratum for entry of the plasticizer.

With a given combination of resin in the layer R and plasticizer in thelayer A, the degree of pressure sensitivity of the layer R may becontrolled within specified limits dependent upon the particular use orintended application of the finished decalcornania. For example, if thefinal decalcomania is to be employed on a relatively smooth hard surfacesuch as glass, only a moderate degree of pressure sensitivity in thelayer "R will be required, but if the decalcomania .is to be applied torelatively rough or difficult surfaces, such as fruit skins or woodsurfaces-ahig-her degree of pressure sensitivity will be desired. In thedecalcomania comprising the present invention, accurate control over thedegree of pressure sensitivity in the adhesive layer R may be exercisedby varying the respective amounts of the resin in the layer R and of theplasticizer in the layer A. If, for example, the finished decalcomaniasare to be applied to the rough, waxy outer surfaces of oranges, it maybe desirable to employ for the activating layer A a steppedup "lacquer,i. e. a nitrocellulose lacquer to which has been added a greater thannormal amount of plasticizer. For other uses, the normal plasticizercontent of the lacquer may suffice. In addition, the ultimate degree ofpressure sensitivity of the layer R may also be regulated by the resincontent of the layer Rand also by the relative thicknesses of the layersR and A.

After the activating layer A has dried to *a non-tacky condition, thedesired transfer design layer P is applied the'reover in any of thewellknownmanner's, such as by printing, screening, or lithographi'ng.Usually, the transfer design is a composite design formed bysuperimposing various colored layers until the desired finaldesign isobtained, such various design printings being indicated by the singlelayer P in the several figures of the drawing. A protective outercoating C of clear lacquer may then be added where necessary ordesirable to protect the printed design during handling and storage ofthe decalcomani'as. The colored inks employed in the application of thelayer P are ordinarily which will-also migrate or diffuse through theactivating layer A into the adhesive layer R and thereby assist inconverting the resinous layer to a tacky, pressure sensitive condition.It is to be noted, however, that although the resinous adhesive layer Rbecomes tacky and pressure sensitive, the later lacquer layers,including the activating layer A and the design layers P, are not in anyway prevented from becoming non-tacky and'from remaining in a toughflexible state.

A decalcomania produced in the manner abovedescribed and according tothe layer arrangement shown in Fig. l is applied in much the same manneras the conventional slip-ofi" transfer. The decalcomania is first dippedin water or the backing B is otherwise wetted with water to soften thegummy layer D. When the water soluble layer D has dissolvedsuificiently, the adhesive layer R and the layers superimposed thereonare released, and the backing sheet B is slid off exposing the pressuresensitive layer R. The decalcomania is then applied by pressing thetacky layer R into contact with the surface to be decorated. Thepressure sensitivity of the layer R provides a firm initial bondingaction which is highly satisfactory in causing the design to adherereadily to all types of difiicult surfaces.

- However, in contrast with the known types of pressure sensitivedecalcomanias, the volatile components in the pressure sensitive layer Revaporate with the passage of time, and by gradual drying andpolymerization of the resinous constituents, the layer R develops into apermanent, tough, strong, scratch resistant bond with the decoratedsurface. Thus, it will be seen that the initial pressure sensitive bondafforded by the tacky layer R is converted by a chemical bondingreaction, after the lapse of time, to a permanent, hard, flexible bondwith the underlying surface.

In Fig. 2 a'slightly modified form of decalcomania embodying themigration principle of the present invention is illustrated. The backingor carrier sheet B coated with the water soluble adhesive layer D andthe resinous adhesive layer R are the same as in the transferillustrated in Fig. 1. However, in this embodiment of the invention thecolor printing ink layer P is applied directly over the adhesive layer Rafter the latter has dried. The activating layer A is applied directlyon the design layer P and serves also to protect the printed designthereby eliminating the necessity for a separate protective coating C.In this form of the invention the plasticizing oils in the activatinglayer A migrate or diffuse downwardly through the printed design layerP, which does not impede or prevent the desired migratory action, andpass in combination with the plasticizer contained in the inks of thelayer P into the adhesive layer R. A decalcomania of the type of Fig. 2may be applied to a surface in the same manner as described above inconnection with Fig. 1 and with the same satisfactory results.

A different type of decalcomania embodying the migration principle isillustrated in Fig. 3. This form of transfer may be characterized as areverse type of decalcomania in that the color printing layer P isapplied directly over the water soluble adhesive layer D carried by thebacking sheet B, and the activating layer A and the resinous adhesivelayer R are applied in the stated order over the printing layer P.Migration of the plasticizing oils from the layers A and P then occursin an upward direction into the adhesive layer R imparting tack andpres- 8 sure sensitivity to the latter. In this form of the invention awater soluble sealer coat S, such as a water soluble glue, gum acacia,dextrine, etc., is applied over the layer R to permit the decalcomaniatobe readily handled and stored. In the application of this type ofdecalcomania,

'the transfer is wetted with water on both sides thereby dissolving thelayer D to permit the transfer to be removed from the backing sheet Band also dissolving the top layer S to expose the tacky, pressuresensitive layer R by means of which the transfer is caused to adhereinitially to the desired surface in the manner hereinbefore described.

Figs. 4 and 5 constitute modified forms of the decalcomania of thepresent invention in which no special activating layer is employed andwhere tack of a relatively low degree is desired. In the embodimentshown in Fig. 4 the color printing layer P is applied directly over theresinous adhesive layer R and the natural plasticizing componentspresent in the inks employed to form the layer P migrate downwardly intothe layer R imparting the desired tack and pressure sensitivity thereto.A protective coating C is provided to prevent injury to the printeddesign P.

In Fig. 5, a reverse type decalcomania is illustrated in which nospecial activating layer is used. The color print P is applied directlyto the dextrine coating D of the backing sheet B, and the adhesive layerR is superimposed on the layer P. The plastioizing components in theinks of the layer P migrate upwardly to the layer R converting thelatter to a tacky, pressure sensitive state. As in the reverse typedecalcomania described in connection with Fig. 3, the form of theinvention illustrated in Fig. 5 also requires a final Water solublesealer coating S for protecting the pressure sensitive layer R until itis desired to use the transfer. The decalcomania shown in Figs. 4 and 5are used in the same manner described above in connection with Figs. 1and 3, respectively, and the adhesive layers, after lapse of time, formrelatively dry, tough, flexible bonds.

Although several forms of decalcomanias with the component layersthereof in various arrangements have been disclosed in Figs. 1 to 5,inclusive, of the drawing, and several specific examples as to theconstituent elements of the adhesive layer and the activating layer havebeen given, it is apparent that modifications in the adaptation of themigration principle may be resorted to without departing from the scopeof the invention as defined in the appended claims.

We claim:

1. A method of forming a pressure sensitive decalcomania which comprisesseparately applying in predetermined sequence over one side of areleasable backing an adhesive material comprising a solution of athermoplastic resin in a volatile solvent and an activating materialcomprising a plasticizer-containing lacquer, permittin the first-appliedmaterial to dry to a normally non-tacky and non-pressure sensitive stateprior to application of the other of said materials, thereafterpermitting said other material to dry to a'normally non-tacky andnon-pressure sensitive state whereby to form separate and initiallynon-pressure sensitive resinous and lacquer layers disposed insuperimposed relation one above the other on said backing, said lacquerlayer containing a suilcient quantity of a readily migratableplasticizer to render said resinous layer tacky and pressure ensitive,and allowing said. plasticizer to migrate to the resinous layer therebyconverting the latter to a tacky and pressure sensitive condition.

2. The method of claim 1 further characterized in that said resincomprises a coumaroneindene resin.

3. A method of forming a pressure sensitive decalcomania having a waterpermeable backing with a water soluble film thereon which comprisesapplying over said film a solution comprising a thermoplastic resin in avolatile solvent, permitting said solution to dry to form a normallynon-tacky and non-pressure sensitive resinous layer, subsequentlyapplying thereover a lacquer containing a sufficient quantity of areadily migratable plasticizer to render said resinous layer tacky andpressure sensitive, and allowing said plasticizer to migrate to theresinous layer thereby converting the latter to a tacky and pressuresensitive condition.

4. A method of forming a pressure sensitive decalcomania having a waterpermeable backing with a water soluble film thereon which comprisesapplying over said film a solution com-prising a thermoplastic resin ina volatile solvent, permitting said solution to dry to form a normallynon-tacky and non-pressure sensitive resinous layer, subsequentlyapplying directly thereover a plasticizer-containing lacquer, permittingsaid lacquer to dry to form a non-pressure sensitive lacquer layer,thereafter applying a transfer design directly over said lacquer layer,said lacquer layer containing a suflicient quantity of a readilymigratable plasticizer to render said resinous layer tacky and pressuresensitive, and allowing said plasticizer to migrate to the resinouslayer thereby converting the latter to a tacky and pressure sensitivecondition.

5. A method of forming a pressure sensitive decalcomania having a waterpermeable backing with a water soluble film thereon which comprisesapplying over said film a solution comprisin a thermoplastic resin in avolatile solvent, permitting said solution to dry to form a normallynon-tacky and non-pressure sensitive resinous layer, applying directlythereover a transfer design film, permitting the latter film to dry,subsequently applying directly over the design film a lacquer containinga suflicient quantity of a readily migratable plasticizer to render saidresinous layer tacky and pressure sensitive, and allowing saidplasticizer to migrate through said transfer design film to said resinoulayer and thereby convert the latter to a tacky pressure sensitivecondition.

6. A method of forming a pressure sensitive decalcomania having a waterpermeable backing with a Water soluble film thereon which comprisesapplying a transfer design over said film, applying aplasticizer-containing lacquer layer directly over said design, applyingdirectly over said lacquer layer a solution comprising a thermoplasticresin in a volatile solvent, permitting said solution to dry to form anormally nontacky and non-pressure sensitive resinous layer, saidlacquer layer containing a sufficient quantity of a readily migratableplasticizer to render said resinous layer tacky and pressure sensitive,and allowing said plasticizer to migrate to the resinou layer therebyconverting the latter to a tacky and pressure sensitive condition.

7. A method of forming a pressure sensitive 10 decalcomania having awater permeable backing with a water soluble film thereon whichcomprises applying over said film a solution comprising a thermoplasticresin in a volatile solvent, permitting said solution to dry to form anormally non-tacky and non-pressure sensitive resinous layer, applyingdirectly thereover a transfer design layer comprising a lacquercontaining a suflicient quantity of a readily migratable plasticizer torender said resinou layer tacky and pressure sensitive, and allowingsaid plasticizer to migrate from said design layer to said resinouslayer and thereby convert the latter to a tacky pressure sensitivecondition.

8. A method of forming a pressure sensitive decalcomania having a waterpermeable backing with a water soluble film thereon which comprisesapplying a transfer design over said film, subsequently applyingdirectly over said transfer design a solution comprising a thermoplasticresin in a volatile solvent, thereafter permitting said solution to dryto form a normally nontacky and non-pressure sensitive resinous layesaid transfer design comprising a lacquer containing a suflicientquantity of a readily migratable plasticizer to render said resinouslayer tacky and pressure sensitive, and allowing said plasticizer tomigrate to said resinous layer and thereby convert the latter to a tackypressure sensitive condition.

9. A decalcomania of the pressure sensitive type prepared in accordancewith the method 01. claim 1.

10. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 2.

11. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 3.

12. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 4.

13. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 5.

14. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 6.

15. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 7.

16. A decalcomania of the pressure sensitive type prepared in accordancewith the method of claim 8.

ALFRED F. GRUPP.

HARRY C. RATHKE. ELWOOD S. TALAN. ELMORE WATTS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,627,407 Reese May 3, 19271,780,021 Laws Oct. 28, 1930 1,826,228 Tull Oct. 6, 1931 2,104,025 DavisJan. 4, 1938 2,271,413 Braverman Jan. 27, 1942 2,359,185 Wysong Sept.26, 1944 2,409,564 Heinecke et al. Oct. 15, 1946 2,453,052 Van EttenNov. 2, 1948

5. A METHOD OF FORMING A PRESSURE SENSITIVE DECALCOMANIA HAVING A WATERPERMEABLE BACKING WITH A WATER SOLUBE FILM THEREON WHICH COMPRISESAPPLYING OVER SAID FILM A SOLUTION COMPRISING A THERMOPLASTIC RESIN IN AVOLATILE SOLVENT, PERMITTING SAID SOLUTION TO DRY TO FORM A NORMALLYNON-TACKY AND NON-PRESSURED SENSITIVE RESINOUS LAYER, APPLYING DIRECTLYOVER THE TRANSFER DESIGN FILM, PERMITTING THE LATTER FILM TO DRY,SUBSEQUENTLY APPLYING DIRECTLY OVER THE DESIGN FILM A LACQUER CONTAININGA SUFFICIENT QUANTITY OF A READILY MIGRATABLE PLASTICIZER TO RENDER SAIDRESINOUS LAYER TACKY ADN PRESSURE SENSITIVE, AND ALLOWING SAIDPLASTICIZER TO MIGRATE THROUGH SAID TRANSFER DESIGN FILM TO SAIDRESINOUS LAYER AND THEREBY CONVERT THE LATTER TO A TACKY PRESSURESENSITIVE CONDITION.